In this description, “direct” thermal printing device is defined as a thermal printing device that is not of the thermal transfer type, i.e. is not of the type in which the ink is transferred through the effect of heat from an intermediate (temporary) disposable support to a normal (definitive) printing support.
In the “direct” thermal printing device in question, the material (ink) intended to form, through the effect of heat, the printing image, is already set up in the veritable printing support (without the need for a transfer from an intermediate disposable support) before traversing the thermal print head.
Specifically, but not exclusively, the invention can be applied to dispense printed documents in real time on thermal paper. The documents can comprise, for example, tickets, receipts, stubs, coupons, vouchers, etc, in particular documents having a particularly delicate or fine printable side, for example a printable side provided with an opaque patina that hides from view what has been printed and which has to be subsequently removed by scraping (“scratch and win” card, “scratch and park” card, etc).
In particular, reference is made to a direct thermal printing device according to the preamble of the first claim. Such a device is widely used for dispensing printed documents in real time on thermal paper.
One of the drawbacks of prior art printing devices is the risk of damage to the printable side of the thermal paper, in particular caused by sliding on the thermal print head.